Magnetically-joinable play tiles

ABSTRACT

A magnetically joinable play tile comprising a tile body having an edge; and a rotatable magnet carried by tile body adjacent to the edge.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application No. 62/379,120, filed Aug. 24, 2016, which is incorporated by reference herein.

BACKGROUND Field of the Invention

The present invention relates to magnetically-joinable play tiles.

Related Art

Magnetically joinable play tiles provide interesting and educational diversion for children. Because they are mainly joined by magnetic force (without snaps, tab/slot pairs, screws, or other fastening means), such tiles (often manufactured in various geometrical shapes such as triangles, rectangles, etc.) can, in play, be arranged and quickly re-arranged into myriad configurations. This invention concerns improvements for such tiles, specifically in the areas of play flexibility and manufacturing cost.

SUMMARY

An aspect of the invention provides additional play flexibility by means of multi-pole self-aligning magnets and mechanical tile alignment supports that allow additional tile assembly variations and more stable tile assembly configurations compared to prior art.

Another aspect of the invention involves a magnetically joinable play tile comprising a tile body having an edge; and a rotatable magnet carried by tile body adjacent to the edge.

One or more implementations of the aspect of the invention immediately above includes one or more of the following: the tile body is a uni-body and the rotatable magnet is carried within the uni-body for rotation therein; the tile body includes a receiving pocket and further including a magnetic cartridge assembly receivable in the receiving pocket, and the magnetic cartridge assembly includes the rotatable magnet therein; the magnetic cartridge assembly includes a mechanical tile alignment support that enables stable edge-to-edge tile assembly; the tile body includes a tile-body cut-out and further including a magnetic cartridge assembly that attaches onto the tile body whereby the magnetic cartridge assembly includes the rotatable magnet therein and the rotatable magnet is disposed in the tile-body cut-out; the magnetic cartridge assembly includes a mechanical tile alignment support that enables stable edge-to-edge tile assembly; a mechanical tile alignment support that enables stable edge-to-edge tile assembly; the rotatable magnet is disposed adjacent to the mechanical tile alignment support; the rotatable magnet is disposed not adjacent to the mechanical tile alignment support; the rotatable magnet is a cylindrical magnets with four poles, two North poles and two South poles; the rotatable magnet includes two two-pole magnets joined end-to-end, forming a four-pole magnet having an abrupt field reversal along its length; the rotatable magnet includes a shape of one of a sphere, a zone of sphere, a segment of sphere, a hemisphere, a spherical sector, an ellipsoid, an oblate spheroid, a prolate spheroid, a conoid, a non-right cylinder, a truncated cylinder, a cone, a truncated cone, a truncated right circular cone, and a frustum of right circular cone; the tiles includes magnet includes a shape of one of a sphere, a zone of sphere, a segment of sphere, a hemisphere, a spherical sector, an ellipsoid, an oblate spheroid, a prolate spheroid, a conoid, a non-right cylinder, a truncated cylinder, a cone, a truncated cone, a truncated right circular cone, and a frustum of right circular cone; the tile body is made of one of corrugated cardboard and paper-faced foam board, and further including a magnetic cartridge assembly that attaches onto the tile body whereby the magnetic cartridge assembly includes the rotatable magnet therein; and/or the mechanical tile alignment support includes one or more of splines, knurled surfaces, rough surfaces, fractal surfaces, adhesive-coated surfaces, hook-loop pairs, tab/slot pairs, rounded/convex ends, rounded/concave grooves, rounded/concave channels.

Other features and advantages of the present invention will become more readily apparent to those of ordinary skill in the art after reviewing the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The details of the present invention, both as to its structure and operation, may be gleaned in part by study of the accompanying drawings, in which like reference numerals refer to like parts, and in which:

FIG. 1 is an isometric schematic drawing of two permanent magnets, showing the “magnetic flux lines” passing through the magnets in a mechanically stable configuration (in this case including a non-magnetic solid [not shown] occupying the volume between the two magnets) in which the two magnets provide attractive force towards one another.

FIG. 2 shows how two magnets (as in an “end view” of FIG. 1) can be embedded into two larger objects so that the two objects exhibit attractive force towards one another due to the embedded magnets within.

FIG. 3 shows early prior art magnetically joinable play tiles with embedded magnets (as in a “top view” of FIG. 1) such that the tiles exhibit attractive force towards one another.

FIG. 4 shows how early prior art magnetically-joinable play tiles of FIG. 3 will exhibit mutual attraction, in either juxtaposition of two tiles, e.g. both as seen in FIG. 3 and also after the triangular tile is “flipped” (rotated 180 degrees around the axis shown).

FIG. 5 illustrates several limitations of the early prior art tiles.

FIGS. 6A and 6B illustrate an embodiment where two cylindrical magnets are embedded into two larger objects (as in FIG. 2) so that the two objects exhibit attractive force towards one another, and the cylinders are allowed to rotate into either one of two stable magnetic attraction configurations “A” or “B”.

FIG. 6C illustrates one aspect of the invention, wherein each cylindrical magnet has four poles (two North and two South), providing shorter, better-contained north-to-south magnetic flux lines in dual-tile and multiple-tile joints.

FIG. 7 illustrates, in a multi-tile joint including a center pole, the short, well-contained magnetic flux line paths via the interfacing poles of the four-pole magnets.

FIG. 8 shows the tile configuration advantages of the freely rotating magnets over the prior art of FIGS. 1-4.

FIG. 9 illustrates another aspect of the invention: mechanical alignment supports as a means for stabilizing edge-to-edge tile joints that are bound by single magnet pairs.

FIG. 10 shows one example of the mechanical alignment supports—a spline that is provided on a half-cylindrical tile edge.

FIG. 11 shows a four-pole magnet in which a pair of two-pole magnets that are joined end-to-end so as to form another type of four-pole magnet that, according to the invention, is an alternative to the magnets of either FIG. 6A or 6C.

FIG. 12 illustrates another aspect of the invention where two two-pole spherical magnets are embedded into magnet—receiving pockets of two larger objects (as in FIG. 2) so that the two objects exhibit attractive force towards one another, and the spherical magnets are allowed to rotate into either one of two stable magnetic attraction configurations “A” or “B”, similar to that described above with respect to FIGS. 6A and 6B.

FIG. 13 illustrates another embodiment of magnetic tiles where the spherical magnets of FIG. 12 are centrally disposed along edges of the tiles and with the tiles including mechanical alignment supports as shown and described with respect to FIGS. 9 and 10.

FIG. 14 illustrates a further embodiment of magnetic tiles where the spherical magnets of FIG. 12 are disposed adjacent to corners of the tiles and with the tiles including mechanical alignment supports as shown and described with respect to FIGS. 9 and 10.

FIGS. 15A and 15B illustrates another embodiment: a two-part realization, comprising 1) a tile, and 2) a magnetic cartridge that is inserted into the tile in order to form a magnetic tile.

FIGS. 16A and 16B illustrate another embodiment: a two-part realization, comprising 1) a tile body, and 2) a magnetic cartridge that is attached to the tile body in order to form a functional magnetic tile.

FIG. 17 illustrates a “building” that is made according to the embodiment of FIGS. 16A and 16B, comprising paper-faced foam board (that is printed with “building” details) and magnet-cartridge assemblies (that have been fastened to the foam board).

DETAILED DESCRIPTION

Magnetically joinable play tiles provide interesting and educational diversion for children. Because they are only bound by magnetic force (without snaps, tabs/slots, screws, or other fastening means), such tiles (which are often manufactured of polymer material by means of injection molding in various geometrical shapes such as triangles, rectangles, etc.) can, in play, be arranged and quickly re-arranged into myriad configurations. This invention concerns improvements for such tiles, specifically in the areas of play flexibility and manufacturing cost.

Mutual attraction of permanent magnets is widely employed in temporary and easily movable fastening applications. As is well known, permanent magnets have “poles” (“north” and “south” modeled after the earth's present natural magnetic field direction), which exhibit an attractive force toward opposite poles of other permanent magnets. Magnetic fields associated with the magnets' poles are modeled by “magnetic flux lines” (continuous lines “circulating” through north and south poles and back around again) as an aid to calculating magnetic forces. In general, attractive forces between two two-pole magnets (each with North and south poles) are in the direction that decreases the length of the flux lines (until mutual contact or other physical barriers prevent further motion of the magnets, thus creating a mechanically stable physical configuration).

FIG. 1 is an isometric schematic drawing of two permanent magnets 10 and 11—showing the magnetic flux lines passing through the magnets in a mechanically stable configuration (in this case including a non-magnetic solid [not shown] occupying the volume between the two magnets) in which the two magnets provide attractive force towards one another.

If two two-pole permanent magnets are embedded into other objects, then the two objects will exhibit a mutual attraction (depending on the magnets' poles' orientation). FIG. 2 shows how two magnets 20 and 21 (as in an “end view” of FIG. 1) can be embedded into two larger objects 22 and 23 so that the two objects exhibit attractive force towards one another due to the embedded magnets within.

Prior art magnetically joinable play tiles have embedded two-pole magnets as to provide temporary and easily movable tile assembly by means of mutual attraction between tiles. FIG. 3 shows prior art magnetically joinable play tiles 34 and 35 with embedded magnets 30, 31, 32 and 33 (as in two attracting sets, each according to the “top view” of FIG. 1) such that the tiles exhibit attractive force towards one another.

Prior art magnetically joinable play tiles have embedded magnets provided in co-linear pairs, with opposite polar orientations, so as to provide attraction along any two similar-length tile edges, such as provided by magnet pairs 43 and 44 along edges 45 and 46 of tiles 41 and 42, respectively, regardless of tile orientation. FIG. 4 shows how prior art magnetically-joinable play tiles 41 and 42 will exhibit mutual attraction, in either juxtaposition of the square and triangular tiles 41 and 42, e.g. both as seen in FIG. 3 and also after the triangular tile is “flipped” (rotated 180 degrees around the axis 40 shown). Both before and after flipping, the tiles' embedded magnets' north/south juxtapositions are the same. This “paired magnet” design is a desirable feature, yet comes with disadvantages that limit play flexibility.

FIG. 5 shows a limitation of the early prior art tiles: if the triangular tile 51 is translated as shown, then the juxtaposed magnets 52 and 53 in tiles 51 and 50 exhibit a repulsive rather than an attractive force—useless for joining tiles. Also shown are two smaller tiles 54 and 55, which, while being “flippable” in orientation, so as to arrange their respective magnets 56 and 57 for attraction to, rather than repulsion from the magnets of magnet pair 58 in square tile 50, yet include a limitation that their single orientations required for attraction to the square tile 50 may not be compatible with the orientations required for their magnets' attraction to those in other tiles—thus limiting play.

A further disadvantage of the early prior art is that the magnets must be provided in pairs, in order to provide the aforementioned attraction along any two similar-length tile edges, irrespective of tile orientation. Since magnets are the most expensive component in a magnetic-tile system, providing them in pairs can result in higher manufacturing cost.

FIGS. 6A and 6B show embedded two-pole magnets that, though embedded, are free to rotate their north/south axes and thus self-align for best mutual attraction with other nearby freely-rotating two-pole magnets. This freedom obviates the need for in-tile edge-axis-paired magnets, as any two-pole magnet in any tile can arrange a stable and mutually-attractive configuration with any two-pole magnet in any other tile.

FIG. 6A illustrates the following function: cylindrical two-pole magnets are embedded into two larger objects (as in FIG. 2) so that the two objects exhibit attractive force towards one another. Though embedded, the cylindrical magnets 61 and 62 are left free to rotate their north/south axes (as shown by the double-ended arrow 62) and to assume (by chance, during the time when the magnets, along with the objects bearing them, are being brought together), either stable magnetic-attraction configurations “A” (exhibited by magnets 60 and 61) or stable magnetic-attraction configuration “B” (exhibited in FIG. 6B by magnets 63 and 64).

An aspect of this invention involves magnetic tiles having improved rotating magnets with four or more magnetic poles. FIG. 6C illustrates cylindrical magnets 65 and 66 with four poles (two North and two South), that can, in stable magnetic-attraction configuration “C”, provide (as represented by dashed lines 67) shorter, better-contained north-to-south magnetic flux lines (than in FIGS. 6A and 6B) in dual-tile and multi-tile joints. Another advantage of the four-pole rotating magnets shown in FIG. 6C is that because of the greater number of poles (compared to the cylindrical magnets shown in FIGS. 6A, 6B) the four-pole magnets will not rotate as much, reducing wear in the magnet-receiving pockets of the tiles. For production convenience, cylindrical four-pole magnets may be built from two identical half-cylindrical magnets (North-South polarized perpendicular to their cylindrical axes, parallel to their diametric planar faces), of which opposing magnetic poles naturally bond together along their diametric faces. However, the four-pole magnets need not be cylindrical.

FIG. 7 illustrates a novel assembly that is supported by four-pole magnets 74, 75, 76, 77 and 78. Edges of up to four tiles 70, 71, 72 and 73 can be assembled to a cylindrical “pole” 79, which provides unique assembly options not included in prior art tile sets. The “multi-tile plus pole” joint is strong, due to short, well-contained magnetic flux line paths via the four-pole magnets' N-S interfaces.

FIG. 8 shows the advantages of freely rotating magnets over the early prior art. FIG. 5's translation problem is solved, as any pair of magnets can (and will) arrange themselves into a mutual-attraction configuration, such as those described in FIGS. 6A, 6B and 6C: magnets 80 and 81 in stable magnetic-attraction configuration “A”, magnets 82 and 83 in stable magnetic-attraction configuration “B”, and magnets 84 and 85 in stable magnetic-attraction configuration “C”. The smaller-tile situation is also improved, as no particular orientation is required either for installing them on any individual magnet of a particular tile, or for subsequently joining the small tile to other tiles—allowing more varied play with additional tile assembly variations.

Since any pair of magnets can arrange themselves into a mutual-attraction configuration, as aspect of the invention eliminates the prior art's requirement of co-linear magnet pairs within each tile (so as to provide assembly in either “flipped” configuration of the tiles, as shown in FIG. 4) whereby only one magnet is required where the prior art requires two magnets.

The cylindrical shape is but one example of the many types of magnet shapes that can be used to realize the aspects of the invention described herein. Other magnet shapes, include, but are not limited to, a sphere, zone of sphere, segment of sphere, hemisphere, spherical sector, ellipsoid, oblate spheroid, prolate spheroid (or any other conoid), non-right cylinder, truncated cylinder, cone, truncated cone, truncated right circular cone, frustum of right circular cone, or other three-dimensional curvilinear body that can be embedded within magnetic play tiles and allowed to rotate freely around an axis.

Another aspect of this invention is shown in FIG. 9. In either “flipped” configuration, triangular tile 91 will still be attracted to square tile 90, yet, with only one magnet bond in the center of the edge-to-edge tile joint, the two edges 92 and 93, absent any preventative measure, could rather easily be dislodged from a parallel configuration, thus providing a less-stable assembly than with the early prior-art magnet-pair bonds along each edge. To prevent this from occurring, this aspect of the invention provides improved stability for the single-magnet edge-to-edge tile joint by means of mechanical alignment supports 94 and 95 that help to maintain the parallel-edge configuration. This aspect of the invention further provides a means to inhibit slippage of joined tiles along their two parallel axes, either by means of further mechanical alignment supports 96 and 97, or by means of the same supports 94 and 95 (according to the type of supports used) that maintain edge-to-edge parallel orientation.

FIG. 9 illustrates one embodiment of a mechanical alignment support system—supports 94 and 95 are splines are provided on tile edges 92 and 93, with the spline grooves parallel to the half-cylindrical tile edges. This configuration enables stable edge-to-edge tile assembly at many different tile-plane angles. Further supports 96 and 97 are splines on tile edges 92 and 93, with the spline grooves perpendicular to the tile edges 92 and 93. These perpendicular grooves inhibit slippage of joined tiles along their two parallel edges 92 and 93. Support features may be realized in other ways, including, but not limited to knurled surfaces, rough surfaces, fractal surfaces, adhesive-coated surfaces, hook-loop pairs, tab/slot pairs, etc. Some types provide both perpendicular and axial support by a single means (e.g. a rough surface), whereas other types provide both types of support by means of two separate features, as shown in FIG. 9.

FIG. 10 shows a detail of FIG. 9's mechanical alignment supports—splines 100 and 101 that are provided on the half-cylindrical edges of tiles 102 and 103, in order to provide stable edge-to-edge tile assembly.

Although the mechanical alignment support(s) are shown as a plurality of splines, in alternative embodiment, the mechanical alignment supports may be, but not by way of limitation, knurled surfaces, rough surfaces, fractal surfaces, adhesive-coated surfaces, hook-loop pairs, tab/slot pairs, etc. Within the implementation where the mechanical alignment support(s) are splines, the splines may have rounded/convex ends and/or rounded/concave grooves or channels. The mechanical alignment support(s) may be one or more mechanical alignment supports disposed at one or more locations along the edge that the magnet(s) is along. The one or more locations may include the corner(s) of the tiles. In a preferred implementation, as shown in FIG. 9, the mechanical alignment support(s) are disposed along the edge, adjacent to opposite corners. In one or more embodiments, the mechanical alignment support(s) may be provided on one or more of the embodiments shown in FIGS. 1-10 (or other magnetic tiles/structures not shown herein).

FIG. 11 shows another example of a mechanical support system to inhibit slippage of joined tiles along their two parallel axes. In this embodiment, the two parallel magnets of either FIG. 6A or 6C are replaced by two-pole magnets 110 and 111 joined end-to-end, and by two-pole magnets 112 and 113 joined end-to-end, each set forming a four-pole magnet having an abrupt field reversal along its length (for example, at a point halfway between its ends), so providing a high force to keep two identical such four-pole magnets, when retained along two separate parallel axes, aligned directly across from one another (with their respective end surfaces 114 and 115 coplanar). Such four-pole magnets, being axially fixed within tiles, and providing edge-to-edge attraction in tiles according to the invention, can inhibit slippage of joined tiles along their two parallel axes.

FIG. 12 illustrates another aspect of the invention where two two-pole spherical magnets 120 and 121 are embedded into magnet—receiving pockets of two larger objects 122 and 123 (as in FIG. 2) so that the two objects exhibit attractive force towards one another, and the spherical magnets are allowed to rotate into either one of two stable magnetic attraction configurations “A” or “B”, similar to that described above with respect to FIGS. 6A and 6B.

FIG. 13 illustrates another embodiment of magnetic tiles where, as described with respect to FIG. 12, the rotating spherical magnets 130, 131, 132, 133, 134, 135 and 136 are centrally disposed along edges of tiles 137 and 138, and with the tiles' edges including mechanical alignment supports as shown and described with respect to FIGS. 9 and 10.

FIG. 14 illustrates a further embodiment of magnetic tiles where, as described with respect to FIG. 12, the rotating spherical magnets 140, 141, 142, 143, 144, 145 and 146 are disposed adjacent to corners of tiles 147 and 148, and with the tiles including mechanical alignment supports as shown and described with respect to FIGS. 9 and 10. In a further embodiment, the magnetic tiles include the spherical magnets of FIG. 12 disposed adjacent to corners of the tiles and the tiles do not include the mechanical alignment supports. In further embodiments, the magnetic tiles include one or more rotating spherical magnets located at one or more locations along the edges of the tiles and/or corners that are the same or different that those shown and described herein.

The magnetic tiles of the aspects, embodiments, and implementations of the invention described herein include different geometric shapes (e.g., squares, rectangles, triangles, polygons). The tiles are preferably made of plastic and injected molded into two halves of a hard plastic material. The magnets are added into magnet receiving pockets of one of the halves, and the halves are assembled/fastened together (e.g., riveted together, snapped together, sonically welded together). In alternative embodiments, the tiles are made of materials other than plastic (e.g., foam) and/or are manufactured by other manufacturing methods.

As an alternate embodiment to inserting magnets into tiles' receiving pockets, magnets may be contained in a magnet-cartridge assembly. Assembled magnet cartridges may be inserted into tiles' receiving pockets. FIG. 15A shows this embodiment: a two-part realization, comprising tile 150 and magnet cartridge 151 that fits into the tile's pockets. The magnet cartridges may include any of the mechanical support systems that are described herein. In FIG. 15, the illustrated magnet cartridge has spline grooves parallel to the half-cylindrical tile edges. FIG. 15B shows how the cartridge comprises cap 152, spherical magnet 153 and cartridge body 154.

In embodiments where the tile material is incompatible with both containing magnets and realizing a mechanical-alignment support system, an attachable magnet-cartridge assembly may be provided. FIGS. 16A and 16B show this embodiment: a two-part realization, comprising tile body 164 and magnet cartridge 163 that is attached to the tile body in order to form a functional magnetically-joinable play tile, by means including (but not limited to) adhesive bonding, mechanical fasteners, mechanical clip action, and so on. The magnet cartridge 163 may be built according to any of the foregoing magnet-configuration embodiments that are described herein. In FIGS. 16A and 16B, the illustrated magnet cartridge has spline grooves parallel to the half-cylindrical tile edges, and spline grooves perpendicular to tile edges.

FIG. 16A shows magnetic cartridge 163 as installed on tile body 164. Cartridge/tile-body overlap area 162 provides area for realization of cartridge/tile-body joining methods. Freely-rotating magnet 160 is mounted in cartridge 163 within a part of cartridge 163 that fits into tile-body cut-out 161 (defined by a dashed line). FIG. 16B is a cross-sectional side view of FIG. 16A, taken through the center of magnet 160, and showing the center section of overlap 162 of tile 164 by cartridge 163.

The two-part embodiment allows tiles to be made of low-cost construction materials such as corrugated cardboard, paper-faced foam board, etc. that can be formed into shapes by die-cutting, for which tooling and production is less expensive than injection molding. By using low-cost material and manufacturing methods, tiles may be inexpensively made much larger than injection-molded tiles. Also, various tile materials may be decorated (by means of popular low-cost printing methods) for colorful appearance or to resemble objects (including but not limited to) houses, castles, boats, military equipment, forts, buildings, trucks, space-travel vessels and so on.

Magnetic assembly of such tiles, while firm enough to provide basic structural integrity, yet would permit “destruction” (i.e. disassembly into constituent tiles) by manual impact or by projectiles. Inasmuch as this type of play is very common (particularly among male children) this embodiment would very likely engender much play. FIG. 17 illustrates a “building” 170 that is made according to this two-part embodiment, comprising paper-faced foam board tile bodies 171, 172, 173, 174, 175 and 176 (that are printed with building details) and magnet cartridges 1701-1714 (that have been fastened to the tile bodies in order to form magnetically-joinable play tiles).

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. Likewise, the various diagrams may depict an example architectural or other configuration for the disclosure, which is done to aid in understanding the features and functionality that can be included in the disclosure. The invention is not restricted to the illustrated example architectures or configurations, but the desired features can be implemented using a variety of alternative architectures and configurations. Indeed, it will be apparent to one of skill in the art how alternative functional, logical or physical partitioning and configurations can be implemented to implement the desired features of the present disclosure.

Although the disclosure is described above in terms of various exemplary embodiments and implementations, it should be understood that the various features, aspects and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described, but instead can be applied, alone or in various combinations, to one or more of the other embodiments of the disclosure, whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments.

Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing: the term “including” should be read as meaning “including, without limitation” or the like; the term “example” is used to provide exemplary instances of the item in discussion, not an exhaustive or limiting list thereof; the terms “a” or “an” should be read as meaning “at least one,” “one or more” or the like; and adjectives such as “conventional,” “traditional,” “normal,” “standard,” “known” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. Likewise, where this document refers to technologies that would be apparent or known to one of ordinary skill in the art, such technologies encompass those apparent or known to the skilled artisan now or at any time in the future.

The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent. 

What is claimed is:
 1. A magnetically joinable play tile, comprising: a tile body having an edge; a rotatable magnet carried by tile body adjacent to the edge.
 2. The magnetically joinable play tile of claim 1, wherein the tile body is a uni-body and the rotatable magnet is carried within the uni-body for rotation therein.
 3. The magnetically joinable play tile of claim 1, wherein the tile body includes a receiving pocket and further including a magnetic cartridge assembly receivable in the receiving pocket, and the magnetic cartridge assembly includes the rotatable magnet therein.
 4. The magnetically joinable play tile of claim 3, wherein the magnetic cartridge assembly includes a mechanical tile alignment support that enables stable edge-to-edge tile assembly.
 5. The magnetically-joinable play tile of claim 1, wherein the tile body includes a tile-body cut-out and further including a magnetic cartridge assembly that attaches onto the tile body whereby the magnetic cartridge assembly includes the rotatable magnet therein and the rotatable magnet is disposed in the tile-body cut-out.
 6. The magnetically joinable play tile of claim 5, wherein the magnetic cartridge assembly includes a mechanical tile alignment support that enables stable edge-to-edge tile assembly.
 7. The magnetically-joinable play tile of claim 1, further including a mechanical tile alignment support that enables stable edge-to-edge tile assembly.
 8. The magnetically joinable play tile of claim 7, wherein the rotatable magnet is disposed adjacent to the mechanical tile alignment support.
 9. The magnetically joinable play tile of claim 7, wherein the rotatable magnet is disposed not adjacent to the mechanical tile alignment support.
 10. The magnetically joinable play tile of claim 1, wherein the rotatable magnet is a cylindrical magnets with four poles, two North poles and two South poles.
 11. The magnetically-joinable play tile of claim 1, wherein the rotatable magnet includes two two-pole magnets joined end-to-end, forming a four-pole magnet having an abrupt field reversal along its length.
 12. The magnetically-joinable play tile of claim 1, wherein the rotatable magnet includes a shape of one of a sphere, a zone of sphere, a segment of sphere, a hemisphere, a spherical sector, an ellipsoid, an oblate spheroid, a prolate spheroid, a conoid, a non-right cylinder, a truncated cylinder, a cone, a truncated cone, a truncated right circular cone, and a frustum of right circular cone.
 13. The magnetically joinable play tile of claim 1, wherein the tiles includes magnet includes a shape of one of a sphere, a zone of sphere, a segment of sphere, a hemisphere, a spherical sector, an ellipsoid, an oblate spheroid, a prolate spheroid, a conoid, a non-right cylinder, a truncated cylinder, a cone, a truncated cone, a truncated right circular cone, and a frustum of right circular cone.
 14. The magnetically joinable play tile of claim 1, wherein the tile body is made of one of corrugated cardboard and paper-faced foam board, and further including a magnetic cartridge assembly that attaches onto the tile body whereby the magnetic cartridge assembly includes the rotatable magnet therein.
 15. The magnetically-joinable play tile of claim 7, wherein the mechanical alignment supports include one or more of splines, knurled surfaces, rough surfaces, fractal surfaces, adhesive-coated surfaces, hook-loop pairs, tab/slot pairs, rounded/convex ends, rounded/concave grooves, rounded/concave channels. 